myRIO - FFT - Aquisition and Sampling Rate

[mbriago]

Hello,

I have a application running very well and I was wondering in an UPGRADE to myRIO-1900, since it is based on FPGA and has wireless connection.

The basic validation was configure acquisition rate and number os samples, and it seemed not to be so straightforward (https://forums.ni.com/t5/LabVIEW/How-to-fft-the-myRIO-accelorometer-readings/td-p/3317681), the applications used in community are slow for medium frequency acquisition and not scalable.

Did I put too much credit believing that a myRIO device could make a simple acquisition and FFT transform? Is it not the correct device to embedded signal analysis, should I look for an arduino application more useful?

Hope you can help me with this issue, I still believe that this application can come true

Best Regards,

[FloresFe]

Hey mbriago,

I am not sure what "medium frequency acquisition" and "not scalable" means to you, so I can't give you an answer righ off the bat. On the other hand, I can definetly say that a myRIO can have a better performance for Data Acquisition and FFT than Arduino. 

Comparing Sampling Rates

1. According to myRIO's Manual, its sampling rate can reach up to 500k Samples/Second aggregated, which means that you should divide this Sampling Rate by the number of channels acquiring simultaneously to get the actual sampling rate per channel. It will depend on the programing method you apply. Using the myRIO tookit, you can acquire between 1kHz and 50kHz.
2. I checked this post from Arduino Forum where users try to estimate an Arduino UNO sampling rate. They came up with a number of approximetly 1k Sample per Second.

Comparing Processing.

1. As you mentioned, myRIO has an FPGA, so it could perform the FFT either in the FPGA chip (fastest way) or in the Real-Time OS.
2. Even if you code the FFT in the Arduino chip, myRIO can deliver you a better preformance, if you code it correctly.

Questions

1. What is bandwidth you want to capture?
2. What do you mean by Scalable?

Below is a couple of links that may help you get what you need.

Analog Input Express VI
https://www.ni.com/docs/en-US/bundle/labview-myrio-toolkit/page/myrioreference/myrioref_exp_ai.html

Required and Optional Software to Program NI myRIO (see the part explaining how you can directly programm myRIO's FPGA)
https://www.ni.com/en/support/documentation/supplemental/13/required-and-optional-software-to-progra...

Sincerely,